Better support for using field names and rule parameters in error messages.
Merge branch 'refs/heads/develop' into feature/form_error_msgs
Merge branch 'develop' of https://github.com/EllisLab/CodeIgniter into feature/form_error_msgs
Merge branch 'develop' of https://github.com/EllisLab/CodeIgniter into feature/form_error_msgs

Conflicts:
	system/language/english/form_validation_lang.php
Fix a merge oopsie in the language file.
Combine this feature with Fix Issue #935 in another pull request.
Better debugging for DB Cache path
Changes per narfbg
Merge pull request #1998 from skunkbad/develop

Better debugging for DB Cache path
Revert a change from 7a7ad782b2f125622509a77c5a6f94ad4ae0f93c

sscanf() is lightning fast, but doesn't have such thing as greediness and this breaks rule parameters containing a closing square bracket.
Improve DB field_data() for MySQL and CUBRID
Improve DB field_data() for MSSQL / SQL Server
Improve DB field_data() for Interbase / Firebird
Improve DB field_data() for SQLite
Improve DB field_data() for Oracle (and fix its max_length for MSSQL / SQLSRV)
Improve DB field_data() for PostgreSQL
Corrected phpdoc comment for mysql_to_unix() method
Merge pull request #2003 from webmasterar/develop

Corrected phpdoc comment for mysql_to_unix() method
Improve DB field_data() for IBM Informix and IBM DB2 (PDO)
Fix issues #751 and #2004